I just did a test and here are the steps of my test:
Rom info:
MD5(Lufia - The Legend Returns (USA).gbc)= a00012533e76649f4e7e1b7aa5a9ee07
EZ-FLASH Junior running 0918 FW5
1. Run the game. after the conversation with blue hair npc. press SELECT to summon map. press START to save.
2. Game will return to the title, I confirm that there is an additional resume in the start screen.
3. Press the RESET button on the card. Backup the save when the kernel booting.
4. Run the game again. and the resume option still there. Choose resume and enter the game ok.
Hello again.
Thank you for taking the time to run a test and outline your process. I have had a chance to perform a similar test. I worry that there are some differences though due to my own misunderstandings, so please correct any errors I have made below, and I can retry.
I have confirmed my ROM on the SD card matches your MD5 checksum perfectly (I am using Hashtab V6.0.0 to confirm)
My test:
1. Run the game. after the conversation with blue hair npc, press SELECT to summon map. press START to save.
2. Game will return to the title. There is no additional "Resume" for me, there is only "New Game" here now.
Possible explanations:
My EZ-FLASH Junior is running the 1.04e and Firmware 4 available here:
https://www.ezflash.cn/download/ I am not sure if this is different from the "0918 FW5" that you describe. I am happy to try that different firmware but I am unsure where to go to download a copy for testing.
My SD card that I am using may be different than yours, or somehow not compatible. I am using the 8GB size of this model:
https://www.teamgroupinc.com/en/product/micro-sdhc-class-10. It has seen limited use so far, and I bought it a year ago.
Thank you again for your time.